Determining how your laser rangefinder will be used is the first step in ensuring that you choose the most useful model for your application. There are rangefinders for hunting, golf, and surveying. This article will deal mainly with golf and hunting rangefinders.
When a rangefinder reads the first object in its line of view and ignores further objects, the rangefinder is said to be in a first priority mode. If it ignores the first object and sees past it to a more distant object the unit is said to be in a second priority mode.
First priority rangefinders are extremely useful on the golf course. There is generally nothing between you and the flag, assuming the flag is not hidden. All golfing rangefinders are in the first priority mode. If you want to range on the flag that is maybe 100 yards away, it will read 100, and not, say, 130, which may be the trees in back of the flag.
Second priority rangefinders are more useful for hunting. A second priority rangefinder used as in the previous paragraph would certainly read the trees at 130 yards and ignore the flag 30 yards closer. In hunting situations you are often in a blind or screened somewhat by limbs or leaves. A hunting rangefinder, or second priority rangefinder would ignore the first object in its line of view such as the branches, and read the most distant object, which may be a deer.
Can you use a golf rangefinder (first priority) for hunting? Absolutely. Can you use a hunting rangefinder (second priority) for golf? Certainly. But the product most closely designed for your intended purpose would be more user-friendly and not require multiple readings or switching modes to ensure the correct distance. Some laser rangefinders offer options to temporarily switch from second priority mode with a "pinpoint" or "bullseye" button (effectively switching from second to first priority) or switching priorities semi permanently.
Rangefinders are sold and marketed under names that imply the maximum readable distance capable with that unit. This causes the most common misconception that consumers have with these units. A unit may be labeled as a 1500 yard rangefinder, and it may be, but only under ideal atmospheric conditions on highly reflective large surfaces!
For instance, without a lot of glare and air pollution and heat waves on a cool day under a cloudy sky, you may be able to range a smooth white metal pole barn at 1500 yards. Add sun or rain or snow or heat mirage, or lessen the size or your target, or darken the color, or increase the texture, then NO! Maybe many hundreds of yards less. In perfect conditions you may see your pole barn at 1500 yards, a dark rocky hill at an oblique angle at 1100 yards, a huge truck at 900 yards, a tree at 700 yards, and a deer at 450 and a flag on the green at even less. Most times a deer may be read at around one third of the maximum stated range, and almost always well under half the distance. Check the manufacturer's specifications.
Reticles and Aiming Points
A reticle is the crosshair (or aiming point or circle) you see when looking through your rangefinder. Some reticles are made of black lines that you superimpose over the object you want to range. These reticles are often impossible to distinguish against a dark background, or in low light conditions such as shadows. Some reticles (or aiming points or circles) appear illuminated because they are actually LED lights. The brightness of these LEDs is invariably adjustable. The issues with LED reticles is that in bright conditions they may be drowned out by the ambient light so they cannot be seen, even at the highest settings, and in the evening, when your eyes are accustomed to the night, the reticles or circles are so bright that they destroy your night vision even at the lowest settings. You are not able to see past the bright reticle. The aforementioned issues with reticles also pertain to other information within your viewing screen such as yardage numbers and modes.
The best of both worlds, in my opinion, is a black reticle and information with a button for backlighting. The backlighting is much less intense than in an LED, and gives you the capability to view your information in all light conditions.